Current collector foil, electrode structure, lithium secondary battery, or electrical double layer capacitor

Abstract

The present invention provides a current collector foil; and an electrode structure, lithium secondary battery or an electrical double layer capacitor using the current collector foil, which can achieve superior high rate characteristics. Provided is a current collector foil for forming thereon an active material layer containing active material particles, wherein: the current collector foil is provided with a roughened portion; a cross sectional curve of the roughened portion has a box counting dimension of 1.1 or higher; and an average length of waviness motif AW of the cross-sectional curve of the roughened portion is longer than twice of D 10 , D 10 being a particle diameter of the active material particle in particle size cumulative distribution, the active material particle being used for the active material layer formed on the current collector foil.

1 . A current collector foil for forming thereon an active material layer containing active material particles, wherein:
 the current collector foil is provided with a roughened portion;   a cross sectional curve of the roughened portion has a box counting dimension of 1.1 or higher; and   an average length of waviness motif AW of the cross-sectional curve of the roughened portion is longer than twice of D 10 , D 10  being a particle diameter of the active material particle in particle size cumulative distribution, the active material particles being used for the active material layer formed on the current collector foil.   
     
     
         2 . The current collector foil of  claim 1 , comprising:
 a metal foil; and   a resin material layer provided on the metal foil; wherein
 the resin material layer contains conductive particles and a binder resin, and 
 the roughened portion is structured by the resin material layer. 
   
     
     
         3 . The current collector foil of  claim 2 , wherein the conductive particles are carbon fine particles. 
     
     
         4 . The current collector foil of  claim 2 , wherein the binder resin contains one type or a combination of two or more types of substance selected from the group consisting of a polyolefin resin, an SBR, a polyimide resin, cellulose and derivatives thereof, chitin and derivatives thereof, chitosan and derivatives thereof, an acryl resin, a butyral resin, a melamine resin, and an epoxy resin. 
     
     
         5 . An electrode structure, comprising:
 a current collector comprising the current collector foil of  claim 1 ; and   an active material layer containing the active material particles, the active material layer being provided on the current collector.   
     
     
         6 . A lithium secondary battery, comprising:
 a current collector comprising the current collector foil of  claim 1 ; and   an active material layer containing the active material particles, the active material layer being provided on the current collector.   
     
     
         7 . An electrical double layer capacitor, comprising:
 a current collector comprising the current collector foil of  claim 1 ; and   an active material layer containing the active material particles, the active material layer being provided on the current collector.